Here's a copy of an old article by Ron Dunnett on snare beds:
Of all of the details and attention to detail that is paid to the various aspects and components that make up a snare drum, the snare bed is probably the most neglected and misunderstood part of the instrument.
Think back to all of the literature you have seen and read about drums and drumming and see if you remember any sort of discussion regarding snare beds. My guess is that like myself, you really won't recall much at all. I'm not sure why this is. Perhaps some companies don't have a grasp on the importance of the snare beds and the role it plays in determining how a snare drum will perform. And it's been my experience that some of them have occasionally forgotten to even install them, let alone discuss them! This was one of the reasons I began making drums...
History
Snare beds appear to have been in use since the earliest days of drum building when the beds were hand hewn with a wood file. While they were somewhat crudely placed, they were some of the best
Definition
The snare bed is the indentation or dip that is located on the bottom bearing edge of the snare drum shell and centered under both the snare release and the butt plate. The length and depth and contour of the beds vary greatly among builders and manufacturers. It is located between the lugs that are located on either side of the throw off and butt end. The snare bed is one of five elements that go into the making of the snare function, the other four being the release mechanism, the snare head, the snare attachment and the snare wire set.
Adjustment Axis
It is important to understand that the snare wire adjustment operates on both horizontal and vertical axis.
The vertical axis is the movement of the snare wire set 'into' the drum head. This adjustment controls the amount of snare set tension, deflection and recoil of the snare set and thus the sensitivity and response of the drum. Deflection and recoil may also be effected by the means used to attached the snares to the throw off and butt.
Snare set control as a Product of Bed Depth
On Dunnett Classic snare drums the range of control is evident in the amount of usable vertical travel. An effective way to illustrate this concept is to take a piece of plastic food wrap and stretch it over the bottom of your snare drum in place of the head so that the surface ofthe film is taught. Next, take a yardstick and lay it across the covered bottom of the drum so that it lies in the center of the drum where the snare wires would normally lie. With one hand on each end of the yard stick push down until you feel the stick touch the bottom of the snare beds. The distance that you are able to push down is the amount of vertical travel your drum has to work with. What happens in a drum that has shallow beds or no beds at all is that vertical travel is limited or non-existant. In this condition virtually any tension that is applied via the throw off mechanism merely stretches the wires along the horizontal surface of the head. Stretching the snare wires in this way severly restricts the movement of the drum head and snare set deflection, thus choking the drum.
Unless the drum is equipped with an adjustable butt end or an independant horizontal tensioning system (ie: Dynasonic), independant horizontal and vertical adjustments cannot be made. In the case of the Rogers Dynasonic system, a bed was not required because the wire set did not extend past the bearing edges and thus it was still possible to have some vertical adjustment. See diagram 1. Independent tensioning systems that do extend past the head do require snare beds. Most snare drums to do not come equipped with an independant horizontal adjustment system and thus they rely on the snare bed... As the snare set is being tensioned from a slack position it is actually being drawn up into the head (vertical axis). When the tension has increased to the point where the wires have "bottomed out" on the snare beds and the snare wire set can no longer up into the head a transition that occurs and any further tensioning past the bottoming point is strictly horizontal - the wires are merely being stretched across the surface of the head. This is usually a problem in snare drums that have shallow or non existent snare beds as this usually results in the drum "choking".
'Choking' is a term used to describe a condition in which the snare wire set and/or the heads have been over tensioned to the point where the snare wires no longer function effectively (negative deflection) or the heads no longer resonate freely. A drum that has a deep snare bed substantially decreases the possiility of choking through an increased range of vertical adjustment.
------------------------------------------------
Hope the info helps...
John
